The present disclosure relates to a ski binding, in particular a ski binding for a cross-country or touring ski, having a binding portion which can be shifted forwards and backwards relative to the ski by activating an actuator coupled to the binding portion.
Skiing and in particular cross-country skiing or touring skiing is a popular winter sport suitable for many people. In the cross-country skiing the arms and legs move parallel to the direction of travel and with the same synchronized rhythm as walking or running. When out walking or running, if every time the skier took a step forward, his/her forward momentum carried twice as far as his/her normal stride would take him/her. That is classical skiing. Classical skiing depends on kicking and gliding. The kick is like a walking or running step; it is how the skier moves forward. Each kick sends the skier gliding down the trail.
Accordingly, the cross-country skis have two distinct base sections. The tip and tail portion of the base are called the “glide zones”. The central portion of the ski is called the “kick zone”. The glide zones are completely smooth. The kick zone may have what is called a “Contagrip” pattern, or fish scales milled into the base. As the skiers step forward, all their weight is on the kick zone and the “Contagrip” pattern is pressed into the snow. As an alternative, the kick zone can be covered with a special wax, the so called “kick wax”. When a skier applies his/her weight to the ski, the kick zone comes in contact with the snow, the kick wax sticks to the snow and the skier is able to move forward. Different kick waxes are used for different conditions and there are a wide variety of kick waxes to match the variations in snow type. This is how classical skiers propel themselves forward. As the skier glides, the kick zone doesn't touch the snow because the skier's weight is spread over the smooth glide zones. During the glide phase, both the skis' tips and tails (the glide zones) will transfer the skier's weight to the snow, providing optimum glide. During the kick phase, the middle ⅓ of the kicking ski (the kick zone) will come into contact with the snow as the skier shifts their weight to just one ski, providing optimum kick. For a fast ski, it is therefore required to provide the skier with a smooth, predictable and consistent transition between the kick and glide phases in all snow conditions.
As it is well known, in order to enjoy this sport properly, it is necessary to have appropriate equipment. In particular, the skis and skis bindings for cross-country skiing must provide an appropriate fastening of the skier's boot to the ski, whilst also allowing the heel of the boot to leave the surface of the ski. An important aspect to be taken into account is the position of the bindings relative to the balance point (neutral balance). Depending on the physiology of the skier and other concomitant factors such as the snow or weather conditions, it could be more convenient to fix the ski behind the neutral point, so that the ski's tip will stay closer to the snow, or to fix the ski in front of the neutral point, so that the ski's tip will rise quicker.
Also, it is known that by properly adjusting the binding forwards and backwards relative to the longitudinal direction of the ski, the skier is able to adapt an individual kick and technique, thus creating a more relaxed and efficient style. In particular, moving the binding forward for classical cross-country skiing gives the skier a better foothold (kick), while moving it backwards gives the skier better glide.
In prior art, there is a variety of arrangements for adjusting front and/or rear jaws of the binding in the longitudinal direction of the ski (see for example DE 39 24 939 A1). However, these arrangements are often complicated in use and difficult to produce.
To find a remedy to this problem, WO 2005/113081 A1 proposes an adjusting device for a cross-country or telemark binding, which is simple to use and does not affect the functional reliability of the binding. In particular, the binding is mounted on the top face of a ski, especially on a mounting plate thereon, so as to be longitudinally displaceable and is lockable in a plurality of sliding positions by means of a locking device.
Although this system has the advantage of adjusting the position of the binding as needed in a simple way, in order to perform this adjustment the skier must stop skiing and take the skis off. This could be a strong hindrance in terms of time consuming, if the skier needs to slightly shifting the position of the binding relative to the skis, in order to quickly improve/optimize for example the kick performance at a ski slope during a ski running.